On Mon, May 27, 2019 at 03:08:07PM +0300, Adrian Hunter wrote:

On 27/05/19 12:37 PM, Brian Masney wrote:

quoted

On Sun, May 26, 2019 at 03:58:19PM -0400, Brian Masney wrote:

quoted

I attached a patch that shows how I was able to determine what had
already claimed the host.

On Mon, May 27, 2019 at 10:48:24AM +0300, Adrian Hunter wrote:

quoted

This is because SDHCI is using the IRQ thread to process the SDIO card
interrupt (sdio_run_irqs()).  When the card driver tries to use the card, it
causes interrupts which deadlocks since c07a48c26519 ("mmc: sdhci: Remove
finish_tasklet") has moved the tasklet processing to the IRQ thread.

I would expect to be able to use the IRQ thread to complete requests, and it
is desirable to do so because it is lower latency.

Probably, SDHCI should use sdio_signal_irq() which queues a work item, and
is what other drivers are doing.

I will investigate some more and send a patch.

Please try the patch below:

From: Adrian Hunter <adrian.hunter@intel.com>
Date: Mon, 27 May 2019 14:45:55 +0300
Subject: [PATCH] mmc: sdhci: Fix SDIO IRQ thread deadlock

Since commit c07a48c26519 ("mmc: sdhci: Remove finish_tasklet"), the IRQ
thread might be used to complete requests, but the IRQ thread is also used
to process SDIO card interrupts. This can cause a deadlock when the SDIO
processing tries to access the card since that would also require the IRQ
thread. Change SDHCI to use sdio_signal_irq() to schedule a work item
instead. That also requires implementing the ->ack_sdio_irq() mmc host op.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Fixes: c07a48c26519 ("mmc: sdhci: Remove finish_tasklet")

Yes, this fixes the issue for me. You can add my:

Reported-by: Brian Masney <redacted>
Tested-by: Brian Masney <redacted>

Thanks,

Brian